Вот ответ от JustHost
John H.: [6:28:55 PM] Welcome to our real-time support chat. My name is John H. Please be patient, as I may be assisting multiple customers. Also, please provide your main domain name, and a brief description of the problem or request. Thank you.
ME: [6:28:55 PM] is memcache enable for share host?
[6:30:01 PM] hi
John H.: [6:30:31 PM] Let me see what I can find out for you. Just one moment please.
ME: [6:30:37 PM] thanks
John H.: [6:41:04 PM] I have asked an L2, and am waiting for a response. sorry for the delay.
ME: [6:41:39 PM] no problem
John H.: [6:41:49 PM] no, it's not enabled.
[6:41:52 PM] we don't support it
ME: [6:42:11 PM] ok thank you
Я бы порекомендовал использовать функцию чата в следующий раз, когда вы или закажете новый общий хост, и спросите представителя, если они включили memcached.